                            (-> construct
                                (dissoc :lang)
                                (set/rename-keys {:construct :value})))]
-    (generate-string (map format-construct sparql-constructs))))
+    {:status 200
+     :headers json-header
+     :body (generate-string (map format-construct sparql-constructs))}))
 
 (defroutes api-routes
   (context "/api" []

            [cheshire.core :refer [generate-string]]
            [clojure.set :as set]))

(defn sparql-query
  "Execute a SPARQL query in an HTTP GET request using `params` and HTTP `headers`."
  [{:keys [query]

                                                 :query-params params
                                                 :throw-entire-message? true}))
      {:status 400
       :headers json-header
       :body (generate-string validation-results)})))

(defn get-exercise-solution
